Your Aerio store name can be changed under the Store - "Style" tab on the Aerio Dashboard. Here, you can update your store's name, tagline and description.
Whenever you make changes to your store name, always scroll down to the blue button and click "Save Changes".
Your store's "Brand Name" will show up whenever a reader is viewing one of your book product pages:
Or whenever a reader is checking a book out from your store:
Your "Tagline" will show up on your store's main page, when you click "View Store" from the Aerio Dashboard: